Tobacco smoking has well-documented negative effects on human health.
Describe how tar in tobacco smoke damages the lungs and reduces the efficiency of gas exchange.
Cigarette smoke also contains carbon monoxide. Explain how inhaling carbon monoxide reduces a person's physical stamina and ability to perform aerobic exercise.
16 exam-style questions on Edexcel IGCSE Biology Gas exchange. Each one has a worked solution and a mark scheme showing where the marks go.